Commonly, an internal combustion engine of an automobile is known to have thermal efficiency of about 15% to 35%, and even at the maximum efficiency of the internal combustion engine, about 60% of the total heat energy is consumed due to heat energy released outside through the walls of the internal combustion engine, associated components and exhaust gasses.
As such, since the efficiency of an internal combustion engine may be increased if the amount of heat energy released outside through the wall of an internal combustion engine is reduced, methods of installing thermal insulation material outside of an internal combustion engine, modifying a part of the structure or material of an internal combustion engine, or developing a cooling system for an internal combustion engine have been employed.
Particularly, if a release of heat generated in an internal combustion engine outside through the wall of the internal combustion engine is minimized, the efficiency of an internal combustion engine and the fuel efficiency of an automobile can be improved. However, studies on thermal insulation material or thermal insulation structures that can be maintained for a long time inside of an internal combustion engine to which high temperature and high pressure conditions are repeatedly applied are insufficient.
Recently, based on the fact that aerogel, a nanosize material, having high specific surface material with high porosity, is effective for improving light weight and thermal insulation properties, various studies have been conducted on mixing of binder compounds and aerogels in order to use aerogel for thermal insulation material inside of an internal combustion engine.
However, due to a failure of appropriate mixing of aerogel and binder compounds or of a penetration of binder compounds into the aerogel according to the surface property of aerogel, an optimum level of thermal insulation property was not reached.
In order to solve these problems, there is a demand for the development of a novel thermal insulation coating composition that can control the surface property of aerogel, and appropriately mix aerogel and binder compounds to maximize thermal insulation property.